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By Raymond J. Isherwood

The U. S. Bureau of Mines has investigated the domestic primary and secondary lead smelting and refining industries to determine the economic impacts of existing and proposed environmental, health, and safety regulations. The impacts are assessed in terms of capital and operating costs for existing and alternative smelting/ refining technologies. Industry response to regulatory implementation is estimated and quantified in terms of import value from lost lead production. For the primary lead industry, regulatory compliance may add up to 1.15 ¢/lb refined lead to operating cost for rehabilitated plants. Alternative smelting/refining methods could reduce net operating costs by as much as 4.36 ¢/lb refined lead. Capital expenditures would vary from $750 to $1,000 per annual mt of smelter capacity. Secondary lead smelter operating costs would increase about 3.8 ¢/lb refined lead to comply with existing regulations. Capital expenditures would average about $124 per annual mt of smelter capacity. Implementation and enforcement of proposed regulations would result in closure of the primary lead industry and additional expenditures for compliance by the secondary lead industry. Enforcement of the most extreme proposed regulations would force the secondary lead industry to close.

Jan 1, 1988

By d&apos, Kathleen J. Amico

THIS summary appears in Minerals Yearbook volumes I and III, which cover mineral production in the United States, its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, as well as the principal minerals imported into and exported from the United States. The several commodity and area chapters contain further details on production. A summary table comparing world and U.S mineral production also is included.

Jan 1, 1964

By N. Kyriazi, W. Duerr, J. Shubilla, J. G. Kovac, J. Kravitz

A joint effort by the Bureau of Mines and the Mine Safety and Health Administration (MSHA), U.S. Department of Labor, was undertaken to determine how well self-contained self-rescuers, deployed in accordance with Federal Regulations (30 CFK 75.1714), held up in the underground environment. This report presents findings regarding laboratory-tested breathing apparatus from the first year of a 5-yr program as well as other related findings. The SCSR's were tested on human subjects and on a breathing and metabolic simulator. These results indicate that the apparatus, if well-treated, perform as expected except for manufacturing defects or quality control problems, which are identified. However, when the apparatus are carried in and out of the mine every day and stored at the working section, they may suffer abuse that can be extreme. Physical signs of abuse, unless extremely obvious, frequently are not detected by the miners or the mine operators; this poses a danger to a potential user in case of emergency. Recommendations include improved training in inspection procedures.

Jan 1, 1986

By George S. Koch

Several methods of calculating ore grades by diamond-drill sampling in the Homestake mine, Lead, S. Dak., have been evaluated by statistical analyses of assay data. The natural distribution of gold particles, partly masked through sampling and assaying procedures, is probably lognormal. As a consequence of the gold particles being clustered rather than randomly distributed within the ore bodies, (1) more mine samples are needed to obtain a specified precision of mean grade than the number predicted by the standard-error-of-the-mean law; (2) the variance of gold values is not inversely proportional to sample volume, and, therefore, small-diameter drill core yields samples nearly as good as larger diameter core; and (3) sampling at 5-foot intervals provides nearly as good results as sampling at shorter intervals.

Jan 1, 1971

By T. E. Gray

This report describes the preparation characteristics of the most significant coal beds in Wise County, Va. It is one in a series of reports planned to determine coals suitable for the production of metallurgical coke, either as mined or after beneficiation. Wise County produced approximately 6,600,000 tons of coal in 1955, of which about 2,110,000 tons was cleaned mechanically. The Federal Geological Survey has estimated that 1,341 million tons of measured and indicated coal reserves remained in the county as of January 1, 1951.

Jan 1, 1958

By Richard L. Rains

The 15,770-acre Worm Creek Roadless Study Area is in southeastern Idaho about 8 miles (mi) west of the northern portion of Bear Lake. U.S. Bureau of Mines personnel examined the roadless, area during the summer of 1984. No mineral resources were identified within the study area. There were no mines or mining claims in the study area in 1984. However, the study area is blanketed with oil and gas leases, but no known productive horizons have been identified within nor nearby. The roadless area is in the Cordilleran fold-thrust belt and is underlain by Paleozoic and Mesozoic marine strata more than 50,000 feet thick. The trace of the Paris thrust fault is 2 to 3 mi east of the study area and has an eastward displacement of about 4 to 7 mi.

Jan 1, 1985

Water infiltration control techniques are designed to reduce the total volume of water entering an underground mine, and thus, reduce the volume of mine water discharge During the development of underground mines, water may be encountered in various quantities This water must be pumped from the mine during active mining, and in many situations, the weight of water removed will be more than the total weight of mineral extracted After abandonment of the mine, infiltrating water either floods the mine workings or discharges from the mine (27, 127) Infiltrating water may enter underground mines from above, below, or laterally through adjacent rock strata Earth fractures such as faults, joints, and roof fractures resulting from surface subsidence are commonly primary causes of water entrance Into abandoned underground mines Factors affecting the quantity of water entering a mine will be the depth of the mine, location of water bearing strata, and ground water flow patterns Investigations of the quantity of water entering underground coal mines have found the average rate of infiltration to range from approximately 6,262 to 10,280 liters per hectare per day (670 to 1,100 gal/acre/day) (27) Water flowing through underground mines flushes pollutants from the mine and may result in their discharge to the environment A reduction in the amount of flow usually results in a reduction in total pollution load discharging from the mine The techniques discussed in this section can be used to reduce the volume of surface and groundwater available to enter the mine system and transport pollutants The selection of a control technique will depend upon the characteristics of the mine system and the expected cost effectiveness of the technique In order for water infiltration control to be effective in controlling mine drainage pollution, the reduction in mine water flow must not be accompanied by an increase in concentration of pollutants (127) REFERENCES 2, 27, 51, 58, 127, 132

Jan 1, 1975

By Ronald D. Hill, Elmore C. Grim

Surface mining drastically alters the ecological characteristics of the area disturbed and in some cases has a decided effect on surrounding areas. Vegetation is removed, topographic features and characteristics are changed, and the original geologic overburden profiles are destroyed. Spoil banks generally are a heterogeneous mixture of rock fragments, rock particles, and soil-sized material derived from the overburden strata. With proper mining techniques, the various strata can be partially or completely segregated. Segregation of over- burden material offers the opportunity to bury the toxic, acid, or salt-pro producing strata under growth supporting material. In some situations, lower strata may have more desirable characteristics than surface material and can be placed near or on the surface. For example, limestone strata appear in some lower overburden profiles that have shale and/or sandstone near the surface. Also, some lower strata have higher nutrient levels that have been leached from the surface. Experience has shown that natural revegetation is a very slow process on strip mined areas. Native vegetation may not be compatible with the environment on the mined areas, for example : 1. Low nutrients in the spoil. 2. Toxic spoils (very acid or highly alkaline ). 3. Surrounding vegetation may be of the climax type and may not have pioneer- or primary-invader-type species present. 4. The seed source may be to far away from the adjacent mined areas. Early attempts to revegetate strip-mined lands with trees also proved to be unsatisfactory as they did not provide the initial ground cover required to stabilize the spoil. Erosion control with trees only may take up to 10 years before the canopies close and an effective cover is established. They are slow to form soil profiles and do not provide effective chemical pollution control until long after planting. A quick growing cover of herbaceous species is necessary to obtain quick stabilization and initial protection against erosion by reducing runoff and rain-drop splash. Vegetative cover will also build up a concentration of organic matter in the soil, which in turn will

Jan 1, 1974

By Foster Fraas

In the separation of a component from a mixture , two fractions are obtained , one containing a high - percentage composition of the component and the other a low - percentage composition . The high - percentage fraction is frequently called the concentrate and the low - percentage fraction the tailing . In many separation processes the recovery is not complete , and the composition of the concentrate decreases as the recovery of the component, which is concentrated , increases . It is this particular class of separations to which this paper is confined .

Oct 1, 1942

By Richard G. Sandberg

Sphalerite concentrates prepared during processing of Missouri lead ores contain small percentages of cobalt and nickel which adversely affect zinc electrolysis. The Bureau of Mines has evaluated solvent extraction and precipitation techniques to remove and recover cobalt and nickel from zinc sulfate solution prior to zinc electrolysis. Prepared zinc sulfate solutions containing about 190 gpl of zinc and 50 ppm of both cobalt and nickel were treated using various combinations of complexing reagents, solvent, pH, concentration, time, and temperature. The following complexing reagents gave the best results: a-nitroso-ß-naphthol, ß-nitroso-a-naphthol, 1,2 cyclohexane dione dioxime (nioxime), di-2-pyridyl ketone oxime, and dimethylglyoxime. These reagents in suitable solvents lowered the cobalt and nickel levels to <0.1 ppm. Stripping the complexed reagents from the solvents was not possible except for nioxime. Direct addition of the appropriate reagent to the prepared zinc sulfate solution resulted in the precipitation of cobalt and nickel. Several possible flowsheets are presented for the removal and recovery of cobalt and nickel. Good zinc deposits were successfully electrowon from zinc sulfate solutions purified by solvent extraction and precipitation.

Jan 1, 1978

By Neil B. Young

Carbonate minerals constitute a major fraction of the oil shale in Colorado&apos;s Green River Formation. Quantification of carbonate minerals is important for the characterization of oil shale, particularly because of their thermal activity in production of oil from shale. The carbonate minerals found in this oil shale are nahcolite (NaHCO3), dawsonite [NaA1(OH)2CO3], dolomite [(Mg1-xFx)Ca(CO3)2], calcite (CaCO3), and ferroan [(Mg1-xFex)CO3]. Although carbonate minerals can be removed by acid extraction from the balance of the oil shale, direct determination of carbonate minerals is complicated by the occurrence of the same cations in more than one mineral. A method for assigning the acid-soluble cations to the individual carbonate minerals was developed from two assumptions based on oil shale geochemistry: (1) Calcite and ferroan do not occur together, and (2) the ratio of iron and magnesium is the same in dolomite and ferroan. These assumptions were tested by the Bureau of Mines by applying the technique for assigning cations to 219 samples from the saline section of the formation. The reported carbonate mineral amounts were compared statistically with X-ray diffraction peak heights, verifying the cation assignment method.

Jan 1, 1975

By Bergerm L. B., S. J. Davenport

"INTRODUCTION Oxygen, because of its vital relationship to man's physical well being, is the most important chemical_ element. It may be breathed, however, only in a rather limited range of concentrations and pressures without producing ill effects. An excess of oxygen may be equally as harmful as too little of it. Because of the importance of these effects, the study of the physiological action of oxygen has received attention for many years and by many investigators. Much of the investigative work has been directed toward determining the limits within which oxygen in abnormal concentrations and at abnormal pressures may be breathed with safety in such applica¬tions as deep-sea diving, work in comprossod-air, aviation, the wearing of apparatus designed to permit entrance into irrespirable atmospheres, and in the therapeutic applications of the medical profession.The Bureau of Mines frequently receives requests for information on the effects of breathing essentially pure oxygen, because of the Bureau's association with the use of self-contained oxygen breathing apparatus for entering irrespirable mine atmospheres, and the use of oxygen in conjunction with artificial respiration as a moans of resuscitation. The purpose of this paper is to summarize briefly the effects upon the human body of the inhalation of oxygen in various concentrations and at various pressures and to give reference to other published information that deals in greater detail with the diverse phases of the subject. The literature in this field is voluminous; therefore, a complete bibliography has not boon presented in this paper. No paper on this subject would be complete without reference to the classic pioneering work of Paul Bert (1) 3/ in this field. Articles such as those of Stadia, Riggs, and Haugaard (2), Bean (3), Specht (4), and others cited contain extensive lists of references that will leadthe reader to information in a degree of detail that is not within the scope of this publication."

Jul 1, 1950

By John Durkin, Roy J. Greenfield

This report discusses the configuration and system deployment for the postdisaster surface seismic system for detecting and locating trapped miners. It analyzes the results of 15 field tests to define a signal model, background noise levels, and subarray performance. A waveform modeling procedure is described and compared with observed waveforms. The resulting similarity indicates that the major factors affecting the signal amplitude, waveform, and spectral character are understood. A model is presented which gives the signal amplitude as a function of source type, source depth, and horizontal off- set between source and receiver. Using this model a curve is presented which gives the range at which a signal will be detected for different signal and noise levels. Finally, and most important relative to the mission of the sys- tem, the ability of the system to detect signals on one or more subarrays is put into a probabilistic framework. For a strong source it is almost certain that a subarray directly over the source will detect the signal. After signal processing, it is highly likely that signals will he detected on sufficient subarrays to locate the trapped miner. Location errors have been found to be less than 100 ft in the majority of cases. Techniques have been used that can reduce the location errors to this level even when soil layer variation between subarrays is severe.

Jan 1, 1981

By Charles L. Kimbell

World political events that occurred subsequent to yearend 1990, but that bear heavily on the global mineral industry, have been of such importance that they cannot be disregaded, and certainly they contribute to any type of "outlook." However, to write of them simply as "forecasts" in an "outlook" section of this study would be to unjustly pretend to status as prophets. Thus, this section covers events that have occurred not as predictions but rather as history. Despite the end of the cold war, the world remained fractionated, at least from the limited perspective of its mineral industry. The fractionation was not so much the result of adversarial politics between countries and groups of countries, although to be sure, such conflicts had not disappeared. Rather, the fractionation was in the widely divergent patterns of performance that resulted from the diverse conditions and problems facing the different countries and country groups.

Jan 1, 1993

By Alexander May

In its role to provide technology to prevent or limit adverse environmental impacts associated with mining or minerals processing, the Bureau of Mines has conducted research at its Tuscaloosa Research Center to asess the environmental impacts of phosphogypsum produced by the Florida phosphate industry. Over the years, stockpiles containing 335 million tons of phosphogypsun have accumulated and the industry continues to generate an additional 33 million tons a year. Samples from approximately 1,000 feet of drill core, obtained from nine stockpiles were characterized using chemical, X-ray diffraction, emission spectrographic, radiological, and physical means. The data developed indicated that phosphogypsum is not a corrosive or toxic hazardous waste as defined by Environmental Protection Agency criteria. Radium concentration averaged 21 picocuries per gram and its content was inversely related to particle sizes. Thirty-nine elements were detected in phosphogypsum; concentrations of these elements did not vary with depth within the stockpiles.

Jan 1, 1982

By J. D. Dixon

The Bureau of Mines investigated the principles of support-rock interaction, based on structural matrix methods which permit mathematical formulation of the problem and computer solution. The principles are given under two main sections: the first discusses the idealization of the tunnel support structural system for matrix analysis; the latter discusses the analysis procedures necessary for carrying out the solution. A general frame matrix computer program and a medium-size computer should be sufficient for carrying out the procedures involved. The example problem consists of a circular tunnel support which is subjected to a uniformly distributed vertical load, Three wall thickness-radius ratios are studied in combination with four support-rock modulus ratios. This problem illustrates the main procedures of the support-rock interaction analysis involved, and examination of the results reveals the influence of the relative rigidities of the support and the rock.

Jan 1, 1971

By Joseph Cervik, Gerald L. Finfinger

This Bureau of Mines publication reviews underground methane drainage pro- grams being conducted in various coalbeds. Equipment used in drainage programs such as drills, underground pipelines, and methane monitoring systems is described.

Jan 1, 1980

By d&apos, Kathleen J. Amico

THIS SUAMMARY is shown in Minerals Yearbook volumes I and III of this series on mineral production in the United States, its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, and on the principal minerals imported into and ex- ported from the United States. The several commodity and area chapters contain further details on production. A summary table comparing world and U.S. mineral production also is included. Mineral production may be measured at any of several stages of extraction and processing. The stage of measurement used in the chapter is normally what is termed "mine output." It usually refers to minerals in the form in which they are first extracted from the ground, but customarily includes for some minerals the product of auxiliary processing operations at or near mines.

Jan 1, 1962

By M. B. Cooke

An analytical method for the determination of the gum-forming material in gasoline has been developed by the Bureau of Mines, during a study nor in progress to determine the best rays for elimination of such constituents from gasoline. This method is similar in principle to that previously described by Smith end Cooke,2 which involved evaporation of e sample of gasoline in a small glass dish. The evaporation was started on an actively boiling steam bath and completed in an air oven at 105°C. In the improved method described below, the stem bath has been replaced by a steam heated oven in which an inert atmosphere is maintained. Air is excluded from the oven, consequently the precision of the determination is increased. Furthermore, evaporating dishes different from those previously described may be used.

Jan 1, 1925

By K. K. Kershner

This report describes an investigation by the Bureau of Mines designed to provide background data for extending and improving the applications of chlorine metallurgy in extracting metals from ores. Optimum conditions are given tor chloridizing galena, sphalerite, and chalcocite by contact with chlorine gas. Petrographic and chemical analyses of the sulfides used in the experiments are listed. Graphs are furnished showing the extent of chloridization of each metal sulfide over the temperature range of the observations. In each case, the first tests were made with the reaction chamber at room temperature. This temperature was increased by regular increments in succeeding tests until the temperature was reached at which quantitative conversion of the sulfide to chloride was observed. The data are also plotted for screen-size fractions of the sulfide minerals investigated. Data show that the extent of metal chloride formation was affected by chloridization time, particle size of the sample, and usually, the temperature of the reaction chamber. At 300° to 400° C. an anomaly was noted for both galena and sphalerite. The temperature at which this anomaly was observed varied according to the particle size of the mineral. Comparisons are made between the chloridizing characteristics of the mineral sulfides and their chemically prepared counterparts.

Jan 1, 1961